The following is based on Korean Patent Application No. 99-50222 filed Nov. 12, 1999, herein incorporated by reference.
1. Field of the Invention
The present invention relates to sound processing, and more particularly, to an apparatus and method for transmitting the sound of a sound producing device to a user together with adjusted external sound.
2. Description of the Related Art
Sound receivers or earphones used when a user listens to sound of sound producing devices have been used for a long time. A typical example of these apparatuses is disclosed in U.S. Des. Pat. No. 410,466. These apparatuses have the same technical basis as apparatuses for protecting hearing by blocking ambient sound and apparatuses for aiding a user to hear ambient sound more clearly.
Various methods for protecting hearing from external noise have been proposed. One of them is disclosed in U.S. Pat. No. 5,551,090. Apparatuses and methods related to a hearing aid for aiding a user to hear ambient sound more clearly are disclosed, for example, in U.S. Pat. Nos. 5,923,764, 5,785,661 and 5,910,997.
Recently, people frequently listen to sound of small and portable sound producing devices using sound receivers or earphones while walking or driving. A method for allowing a user to conveniently carry a portable sound producing device with associated earphones is disclosed in U.S. Pat. No. 5,845,197.
These sound receivers and earphones described above are related only to hearing of sound from sound sources. However, apparatuses for bidirectional sound transmission have been developed. U.S. Pat. No. 5,907,538 discloses an apparatus for simultaneously generating audio output and receiving audio input. Bidirectional earphone function can be achieved through this apparatus.
When using these sound receivers and earphones, it frequently happens that users do not hear ambient sound, for example, an alarm whistle which may be a danger signal, a warning voice or a calling sound. In this case, the user him/her self may be in danger or may be placing those around him/her self in danger. One of the methods for solving this problem is an integrated sound/telephone headset system disclosed in U.S. Pat. No. 5,694,467. According to this system, a user can hear audio sound, telephone ringing sound and ambient sound through a microphone in a bypass mode according to the user""s selection. When there is an incoming call, the user can convert the bypass mode into an operational mode to answer the phone. At the end of the conversation, the user can go back to the bypass mode through selection. However, this system is limited in usage and does not guarantee that a user will hear a danger signal.
To solve this problem, a method for allowing a user to hear ambient sound by piercing minute holes at the portion of a sound receiver or an earphone contacting the user""s ears has been attempted. However, the problem that a user cannot hear ambient sounds well is not overcome when the volume of the sound from a sound producing device is high. Moreover, the sound of a sound producing device comes out of the sound receiver or earphone through the minute holes and may disturb and annoy other people as noise.
To solve the above problems, it is an object of the present invention to provide an apparatus and method for transmitting the sound of a sound producing device to a user together with adjusted external sound.
Accordingly, to achieve the above object, the present invention provides an apparatus for transmitting a reproduced sound signal of a sound producing device. The apparatus includes an external sound receiver for receiving external sounds and converting them into an external sound signal, a volume controller for outputting only,the reproduced sound signal and the external sound signal having a volume exceeding a predetermined reference level, and a mixer for mixing the reproduced sound signal with the reproduced and external sound signals output from the volume controller and outputting the result.
To achieve the above object, the present invention also provides a method for transmitting a reproduced sound signal of a sound producing device. The method includes the steps of (a) receiving the reproduced sound signal from a sound producing device and an external sound signal corresponding to ambient sounds, (b) transmitting only the reproduced and external sound signals having a volume exceeding a predetermined reference level, and (c) mixing the reproduced sound signal with the sound signal transmitted in the step (b) and outputting the result.